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PICkit 1 FLASH Starter Kit User's Guide

1. Y dWnd ddA gsnA LON LN Kai SEW ZHW9 A RS LA ZE DS40051C page 63 2003 Microchip Technology Inc PICkit 1 FLASH Starter Kit User s Guide PROTOTYPE 1 FIGURE A 5 9 jo G jeeus YOS ZAPYLWAd uupu llj NOLYO4 d Aq umbug FOBC CL LB 9 0q 00L LOTTO J qwny LIM YALYVLS HSV14 Lu MOI HOS ent 134905 Nid CIOS ANA A 934 AS GH CW Pl vl QSHOLIMS S 0 UN 310 89 V34V ONIdALOLOYd 44JO dVNS Nid vl 031V1Nd0d 38 LON TIIM 133HS SIHL NO SLNJNOdWOO JHL 40 TV y 2003 Microchip Technology Inc DS40051C page 64 Hardware Schematics PROTOTYPE 2 FIGURE A 6 9 JO 9 jeeus 00L L ck JequnnN LIM YSLYVLS HSV14 l HII HOS y9S ZA9Y LIDIA uupu j EOBZEL LO eq L 10 9 0q SIT 3adICECKVA CN 939 AG G4S1LVINdOd 38 LON TIIM 133HS SIHL NO SLNSNOdWOO 3H1 40 TV Q DS40051C page 65 2003 Microchip Technology Inc PICkit 1 FLASH Starter Kit User s Guide NOTES DS40051C page 66 O 2003 Microchip Technology Inc Hardware Schematics NOTES 2003 Microchip Technology Inc DS40051C page 67 MICROCHIP WORLDWIDE SALES AND SERVICE AMERICAS Corporate Office 2355 West Chandler Blvd Chandler AZ 85224 6199 Tel 480 792 7200 Fax 480 792 7277 T
2. MICROCHIP PICkit 1 FLASH Starter Kit User s Guide 2003 Microchip Technology Inc DS40051C Note the following details of the code protection feature on Microchip devices Microchip products meet the specification contained in their particular Microchip Data Sheet Microchip believes that its family of products is one of the most secure families of its kind on the market today when used in the intended manner and under normal conditions There are dishonest and possibly illegal methods used to breach the code protection feature All of these methods to our knowledge require using the Microchip products in a manner outside the operating specifications contained in Microchip s Data Sheets Most likely the person doing so is engaged in theft of intellectual property Microchip is willing to work with the customer who is concerned about the integrity of their code Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code Code protection does not mean that we are guaranteeing the product as unbreakable Code protection is constantly evolving We at Microchip are committed to continuously improving the code protection features of our products Attempts to break microchip s code protection feature may be a violation of the Digital Millennium Copyright Act If such acts allow unauthorized access to your software or other copyrighted work you may have a right to s
3. 2003 Microchip Technology Inc DS40051C page 60 Hardware Schematics LED LAYOUT FIGURE A 2 S H 907 Saus YOS ZAPYLIMOd Spuet Now d q umoag 2007 21 10 230 00LLO E0 BA Jaquinn 9ZIS LIM YSLYVLS HSV14 La HII HOS emt OCL e AAA vu Su 033 OI aN 14 oq l i OCL Ly 033 da3 gx ai Gay aq 033 Gay a SC ala 4 sii 80 ji o 0 a 4 OCL WW Sw GSLVINdOdNN NIV gY 33 LLG NYHL 8d 033 EN Ci 033 033 7 2 0 ca Lay ed OCL l AAA va CA EA DS40051C page 61 O 2003 Microchip Technology Inc PICkit 1 FLASH Starter Kit User s Guide VPP SUPPLY FIGURE A 3 g 49 199 US YOS ZAPYLWADId uupu 4 NOLHO1 d Aq UMDAIJ COOZ Cl 1D 3400 QQ lO 0 K J quunN 9ZIS LIM YALYVLS HSV14 L HOI HOS oly VOBENZC CO PEN CC vO 12903334 ddA LL8SNL AOL Ch w dN nd ddA GA 06 NZ ZO 2003 Microchip Technology Inc DS40051C page 62 Hardware Schematics USB CONTROL FIGURE A 4 9 JO jeeus NOLYO4 d Aq umbug LIM YSLYVLS HSV14 L HAOId HOS LP O ox LO D CN MX LO AG Y9S ZA9Y LYADIA SLUDUA Y SQB Z CL LO 9 0q asf 318vN3 OO ASng MOTA AY VLC OLE Sly AG dS SVZLO091 Old A4OCC _1 SO EE
4. Within The Tolerance Adjust OSCCAL Down END CHECKPW W PW Pulse Width EEE et 2003 Microchip Technology Inc DS40051C page 45 PICkit 1 FLASH Starter Kit User s Guide NOTES DS40051C page 46 O 2003 Microchip Technology Inc PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Chapter 3 Working with the Tutorial Software 3 1 INTRODUCTION This chapter covers information needed to work with the tutorial software presented in Chapter 2 3 2 HIGHLIGHTS e Using the Tutorial Source Code e Loading a Project 33 USING THE TUTORIAL SOURCE CODE The source code files for each tutorial are provided on the CD ROM In order to use the tutorial code you will have to 1 Create anew MPLAB project 2 Configure the project for the PIC12F675 3 Add the code to the project 4 Compile the software Details for each of these steps can be found on the MPLAB IDE v6 xx Quick Start Guide available on the MPLAB IDE CD ROM included with the PICkit 1 FLASH Starter Kit MPLAB is the integrated development environment supplied by Microchip Technology Inc for developing software for PIC microcontroller MPLAB is used to Create source code using the built in editor Assemble compile and link source code using various language tools An assembler linker and librarian come with MPLAB IDE Supported C compilers are available from Microchip Third party compilers may be supported also Check the release notes
5. pickit Comp bs C Projects pickit Comp 0 Lal EK El PC Projects pickitl Comparator comp mcp E CiProjectsipickitiComp_Cicomp_c mcp E Source Files EN SOUrCE Files comp asm i E Header Files oo P12F675 1INC x Object Files Object Files Library Files Library Files Linker Scripts 2003 Microchip Technology Inc DS40051C page 31 PICkit 1 FLASH Starter Kit User s Guide 2 6 2 Analog to Digital Converter Tutorial This tutorial uses the PIC12F675 and demonstrates an interrupt based analog to digital conversion TMRO is set up with a prescaler of 4 thus creating an interrupt roughly every 1 ms With every TMRO interrupt either the LED display routine is serviced see Tutorial 3 Section 2 5 or the A D routine is serviced depending on the flag that toggles with every interrupt Noise is generated on VDD when the LED s are updated Therefore to reduce noise in the A D process either a new A D conversion is done or the display is updated but not simultaneously The A D interrupt source is not used because the service interval 2 ms is much longer than the conversion period of 22 us The A D module requires at least 4 us for the sample capacitor to charge between acquisitions but the program allows for about 2 ms The result of the A D is 10 bits even though only the eight most significant bits are displayed on the LED s The result is left justified ADFM 0 and the most significant byte is written to the
6. DS40051C page 27 PICkit 1 FLASH Starter Kit User s Guide 2 5 3 Applications This program is useful in the following applications 1 Displaying an 8 bit value onto the LED array See Section 2 6 Tutorial 4 on using the analog to digital converter for reading an analog potentiometer and displaying its value on the LED array 2 Detecting a button push immediately 3 Flashing LED Patterns See Section 2 7 Tutorial 5 and Section 2 8 Tutorial 6 for displaying different LED patterns stored in data tables 2 5 4 Running The Demo 1 Program the ledint hex code to the PIC12F6XX 2 After the HEX file is programmed to the device the LED array displays all 8 LED s that appear to be on To change the rate at which the LED s are flashed push the SW1 button 2 5 5 Modifying The Source Code 2 5 5 1 FILES REQUIRED FOR PROGRAM MODIFICATION Assembly Source Code e ledint asm Main file that contains the main program and interrupt routine e ledint h Header file that defines the external program variables and routines e intlib675 o or intlib629 o Library file that contains the Display and Debounce routines for the PIC12F675 or PIC12F629 respectively e 12f629 Ikr or 12f675 1kr Linker Script for PIC12F629 and PIC12F675 respectively Linker Script located in C Program Files MPLAB IDE MCHIP_TOOLS FIGURE 2 7 MPLAB PROJECT SETUP ASSEMBLY bes ledint mcw OP x be F MikeR DemoB Mal ES El F MikeR
7. Data Memory Checksum The checksum is calculated on the first N words of the program memory and the first Ng bytes of the data memory Ny and Ng are both words passed as the length parameter The return value is 3 bytes in length the first word is the Program Memory checksum and the last byte is the Data Memory Checksum V lt byte gt Power and special feature control The byte following command is used to control VDD power to the target and to enable disable a 2 5 kHz 50 square wave v Return version information The following bytes are returned lt Major gt lt Minor gt lt Dot gt Z No operation Use to pad packets to 8 bytes Note Word values are sent low byte first Source code files are located on the PICkit 1 FLASH Starter Kit CD 2003 Microchip Technology Inc DS40051C page 53 PICkit 1 FLASH Starter Kit User s Guide NOTES DS40051C page 54 O 2003 Microchip Technology Inc PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Chapter 5 Troubleshooting 5 1 INTRODUCTION This chapter describes common problems associated with using the PICkit 1 FLASH Starter Kit and steps on how to resolve them 5 2 FAQS 5 2 1 Program Does Not Work Question My program does not work What should check Answer 1 Are the configuration bits set in the source file PICkit 1 FLASH Starter Kit depends on having the configuration bits set in the HEX file The assembler uses the CONF
8. EZE Tele LO le EE D 1 3 PICkit 1 FLASH Starter Kit Contents 5 1 4 Running the PICkit 1 FLASH Starter Kit Default Demonstration 5 To HEN TEE 5 16 Using the PICkit 1 FLASH Starter Kit Programming Interface 6 Chapter 2 Tutorial Projects 2 EE 13 2 2 A 13 23 Tutorial 1 Switch DEDOUNCING 13 2 4 Tutorial 2 Introduction to State Machines 20 Zo PULON a pupu u RE PE RP ias 27 2 6 Tutorial 4 Analog to Digital Converters and Comparators 31 2 7 Tutorial 5 Program Memory Look up Routines 34 2 8 Tutorial 6 Data EE Look up Routines 37 2 9 Tutorial 7 Frequency Counting with Timer1 Gate 40 Chapter 3 Working with the Tutorial Software Sel o ASP 0D EC PEO In 47 232 Te tute Le E 47 3 3 Using the Tutorial Source Code oocoocconccccccocccoccocncococonoooncocncanononos 47 3 4 Jaen Project In MPLAB c uuu upan ace 48 Chapter A PICkit 1 FLASH Starter Kit Hardware oe de Lal UC HOM EE EE 51 A2 A on o 51 4 3 In Circuit Serial Programming ICSP Techniques 91 4 4 Programming Hardware Vs 51 4 5 USB Communications Protocol 53 Chapter 5 Troubleshooting e NEEN o e ele Let RE 55 NEE 55 Appendix A Hardware Schematics ze
9. FLASH Starter Kit Appendix A Hardware Schematics Illustrates the PICkit 1 hardware schematic diagrams Glossary A glossary of terms used in this guide Index Cross reference listing of terms features and sections of this document Worldwide Sales and Service A listing of Microchip sales and service locations and telephone numbers worldwide 2003 Microchip Technology Inc DS40051C page 1 PICkit 1 FLASH Starter Kit User s Guide Conventions Used in This Guide This manual uses the following documentation conventions Table Documentation Conventions Description men em Filenames and paths c autoexec bat Curly brackets and pipe Choice of mutually exclusive errorlevel 0 1 character arguments An OR selection Lower case characters Type of data filename in quotes Ellipses Used to imply but not show list additional text that is not relevant to list option the example Ge oy list option Oxnnn A hexadecimal number where n is a OxFFFF 0x007A hexadecimal digit Italic characters A variable argument it can be either a char isascii char type of data in lower case characters ch or a specific example in upper case characters Interface Arial font Underlined italic text A menu selection from the menu bar File gt Save with right arrow Bold characters A window or dialog button to click OK Cancel Characters in angle A key on the keyboard lt T
10. LEDREGISTER to be displayed The ANSEL register specifies which of the general purpose l O pins are to be configured as analog inputs to the A D module In this case the potentiometer s output serves as the input to ANO Figure 2 12 shows the source code files for the assembly and C projects respectively FIGURE 2 12 ASSEMBLY AND C SOURCE CODE FILES imi C Projects pickit C Ol EX E EXWINDOWSA Desktop ork I KE Er C Projects pichit c AD ata C iProjects picki Et Source Files o Library Files E Object Files Er Linker Scripts ntib675 obj H 125 ler e Library Files Linker Scripts DS40051C page 32 2003 Microchip Technology Inc Tutorial Projects FIGURE 2 13 ANALOG TO DIGITAL CONVERSION Timer0 Overflow Interrupt Is A D Service Read Flag Set A D Register Update LEDs Toggle A D Service Flag 2003 Microchip Technology Inc DS40051C page 33 PICkit 1 FLASH Starter Kit User s Guide TUTORIAL 5 PROGRAM MEMORY LOOK UP ROUTINES There is often a need to store constants or strings in a PIC microcontroller Storing this information in program memory is the best solution as long as this data never needs to change and program memory is available Program memory is non volatile therefore it will maintain information regardless of VDD voltage levels or PIC microcontroller reset This tutorial demonstrates how to retrieve data from Program Memory lt covers the following topics e What a pr
11. Latest Microchip press releases Technical support section with FAQs Design tips Device errata Job postings Microchip consultant program member listing Links to other useful web sites related to Microchip products Conferences for products development systems technical information and more Listing of seminars and events 2003 Microchip Technology Inc DS40051C page 3 PICkit 1 FLASH Starter Kit User s Guide CUSTOMER CHANGE NOTIFICATION SERVICE Microchip started the customer notification service to help customers stay current on Microchip products with the least amount of effort Once you subscribe you will receive email notification whenever we change update revise or have errata related to your specified product family or development tool of interest Go to the Microchip web site www microchip com and click on Customer Change Notification Follow the instructions to register The Development Systems product group categories are e Compilers e Emulators e In Circuit Debuggers e MPLAB IDE e Programmers Here is a description of these categories Compilers The latest information on Microchip C compilers and other language tools These include the MPLAB C17 MPLAB C18 and MPLAB C30 C Compilers MPASM and MPLAB ASM30 assemblers MPLINK and MPLAB LINK30 linkers and MPLIB and MPLAB LIB30 librarians Emulators The latest information on Microchip in circuit emulators This includes the MPLAB ICE 2000
12. NN e de el O DEE 59 A2 GA u 22 AA AA 59 Worldwide Sales and Service 68 2003 Microchip Technology Inc DS40051C page iil PICkit 1 FLASH Starter Kit User s Guide NOTES DS40051C page iv O 2003 Microchip Technology Inc PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Preface INTRODUCTION This chapter contains general information about this user s guide and customer support that will be useful prior to using the PICkit 1 FLASH Starter Kit HIGHLIGHTS Items discussed in this chapter are About this Guide Warranty Registration Recommended Reading Troubleshooting Microchip On Line Support Customer Change Notification Service Customer Support ABOUT THIS GUIDE This document describes how to use the PICkit 1 FLASH Starter Kit The manual layout is as follows Chapter 1 Using the PICkit 1 FLASH Starter Kit An overview of the PICkit 1 FLASH Starter Kit and instructions on how to use it Chapter 2 Tutorial Projects Tutorials that describe the different concepts in controlling the PIC microcontroller Chapter 3 Loading Projects in MPLAB IDE A quick overview on how to load a project in MPLAB IDE Chapter 4 PICkit 1 FLASH Starter Kit Hardware Instructions on Programming the PICkit 1 FLASH Starter Kit Hardware Chapter 5 Troubleshooting Provides resolutions for solving common problems with the PICkit 1
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14. and MPLAB ICE 4000 In Circuit Debuggers The latest information on Microchip in circuit debuggers These include the MPLAB ICD and MPLAB ICD 2 MPLAB The latest information on Microchip MPLAB IDE the Windows Integrated Development Environment for development systems tools This list is focused on the MPLAB IDE MPLAB SIM simulator MPLAB IDE Project Manager and general editing and debugging features Programmers The latest information on Microchip device programmers These include the PRO MATE II device programmer and PICSTART Plus development programmer CUSTOMER SUPPORT Users of Microchip products can receive assistance through several channels e Distributors e Local Sales Office e Field Application Engineers FAEs e Corporate Applications Engineers CAES e Systems Information and Upgrade Hot Line Customers should call their distributor or field application engineer FAE for support Local sales offices are also available to help customers See the last page of this document for a listing of sales offices and locations Corporate applications engineers CAEs may be contacted at 480 792 7627 Systems Information and Upgrade Line The Systems Information and Upgrade Information Line provides system users with a listing of the latest versions of all of Microchip s development systems software products Plus this line provides information on how customers can receive the most current upgrade kits The In
15. during the programming sequence If this error is displayed write the program to the device again If this error continues see Chapter 5 for troubleshooting FIGURE 1 4 WRITE ERROR STATUS BAR Head Device d I I u Verity Erase Quit Device Configuration Device PICT2F65 Configuration Word Ds2044 User IDs DEE OSCCAL Dx3FFF CheckSum 014 Bandgap 02000 2003 Microchip Technology Inc DS40051C page 7 PICkit 1 FLASH Starter Kit User s Guide 1 6 2 Automatic File Reload Prior to each write the time stamp is compared to the version on the disk If the version on the disk is newer it is reloaded This occurs only when a HEX file has been read from the disk In the normal mode of operation the HEX file is updated with every build in MPLAB IDE This ensures that the latest version built by MPLAB IDE will be written to the device 1 6 3 Verify Program Code This function verifies the program written to the device against a HEX file lt compares all areas of memory including Program EEDATA and Configuration To verify the code import the HEX file and click Verify If the code is the same the status bar turns green and displays Verified successfully as shown in Figure 1 5 FIGURE 1 5 CODE VERIFY STATUS BAR Read Device Write Device l Device Configuration Device PICTZFB75 Configuration Word Ox3FC4 User IDs OxfF RF FF FF OSCOAL UE CheckSum ZOE Bandgap SUN Ifa discrepancy is found the statu
16. microcontroller application Mechanical switches are inexpensive simple and reliable In addition switches can be very noisy The apparent noise is caused by the closing and opening action that seldom results in a clean electrical transition The connection makes and breaks several perhaps even hundreds of times before the final switch state settles The problem is known as switch bounce Some of the intermittent activity is due to the switch contacts actually bouncing off each other Imagine slapping two billiard balls together The hard non resilient material doesn t absorb the kinetic energy of motion Instead the energy dissipates over time and friction in the bouncing action against the forces push the billiard balls together Hard metal switch contacts react in much the same way Also switch contacts are not perfectly smooth As the contacts move against each other the imperfections and impurities on the surfaces cause the electrical connection to be interrupted The result is switch bounce The consequences of uncorrected switch bounce can range from being just annoying to catastrophic For example imagine advancing the TV channel but instead of getting the next channel the selection skips one or two This is a situation a designer should Strive to avoid Switch bounce has been a problem even before the earliest computers The classic solution involved filtering such as through a resistor capacitor circuit or through re settable sh
17. or readme files for details Debug the executable logic by watching program flow with the built in simulator or in real time with the MPLAB ICE 2000 emulator or MPLAB ICD 2 in circuit debugger Third party emulators may also be supported Check the release notes or readme files for details Make timing measurements with the simulator or emulator View variables in watch windows Additional information concerning the capabilities and the use of MPLAB is available on the MPLAB CD ROM 2003 Microchip Technology Inc DS40051C page 47 PICkit 1 FLASH Starter Kit User s Guide 3 4 LOADING A PROJECT IN MPLAB Loading a project in MPLAB IDE is accomplished with the following steps 1 Launch MPLAB IDE 2 Select Project gt Open as shown in Figure 3 1 3 Browse and locate the project 4 Click OPEN FIGURE 3 1 OPEN PROJECT x MPLAB IDE File Edit View Project Debugger Programmer Configure Dus ta bell New rr Ea Untitled Wo Set Active Project Quick build no asm file Alt F 10 Mean 3 4 1 Compiling the Project After loading a project it is necessary to compile it Select Project gt Make as shown in Figure 3 2 A window will appear and show the progress If there are no errors the program can be simulated or downloaded into the PICkit 1 FLASH Starter Kit software See Chapter 2 for instructions on downloading the program FIGURE 3 2 COMPILE PROJECT aa MPLAB IDE File Edit View Projec
18. wave signal that when selected is input to pin 3 of the Evaluation Socket See Figure A 1 in the Appendix This function is used by Tutorial 7 Section 2 9 and for OSCCAL regeneration FIGURE 1 13 BOARD CONTROLS Board Controls M Device Power 2003 Microchip Technology Inc DS40051C page 11 PICkit 1 FLASH Starter Kit User s Guide NOTES DS40051C page 12 O 2003 Microchip Technology Inc PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Chapter 2 Tutorial Projects 2 1 INTRODUCTION The tutorials in this chapter describe the different concepts in controlling the PIC microcontroller Each tutorial includes instructions for running a program demo that illustrates each of the concepts listed below in Section 2 2 It is necessary to follow the tutorials in the listed sequential order for each tutorial builds upon the previous one The HEX files and source code for the tutorials can be found on the CD 2 2 HIGHLIGHTS The following tutorials are discussed in this chapter Tutorial 1 Switch Debouncing Tutorial 2 State Machines Tutorial 3 Interrupts Tutorial 4 Analog to Digital Converters and Comparators Tutorial 5 Data Tables in Program Memory Tutorial 6 Using EEPROM Memory Tutorial 7 Frequency Counting with Timer1 Gate 2 3 TUTORIAL 1 SWITCH DEBOUNCING Mechanical switches play an important and extensive role in practically every computer microprocessor and
19. 3 04 ps 06 07 ps p pio on ee ee ee G ee GP2 z Z Low Hi Low HI H Low z z z opi Z Z Z Z Z Z LOW o Low HI Low HI Legend HI gt Logic 1 LOW gt Logic 0 and Z gt TRISIO 1 2 5 2 Implementation The tutorial utilizes interrupts to make the LED operation transparent to the main program The main program writes the value OxFF to the LEDREGISTER This flashes 8 LED s on the PICkit 1 FLASH Starter Kit board In order to flash 4 LED s for example write OxOF into the LEDREGISTER The interrupt service routine uses a Timer0 interrupt for updating the LED array A GP3 pin change interrupt detects a button push The Timer 0 prescaler is adjusted and changes the amount of time it takes for a TimerO interrupt to happen This gives the visual representation that the LED s are all on at the same time or Sequencing This tutorial introduces the intlib library The intlib library contains the core functions for flashing the LEDs and debouncing the GP3 push button The intlib library contains the functions Display and Debounce The library also contains the general purpose register LEDREGISTER to flash LEDs See Section 2 9 5 Modifying the Source Code for more information on the required files needed to build this project in MPLAB Also see the source code files for additional comments on the implementation For a high level flowchart see Figure 2 10 2003 Microchip Technology Inc
20. ATE MACHINES State Machines are an integral part of software programming State machines make code more efficient easier to debug and help organize the program flow State machines are not limited to just firmware they can be used to streamline any system However this document limits the scope of state machines to microcontroller firmware 2 4 1 Design 2 4 1 1 WHAT IS A STATE MACHINE A Finite State Machine FSM is based on the idea of there being finite number of states for a given system For instance when an application turns an LED on and off two states exist one state is when the LED is on and the other is when it is off The example firmware that this document refers to turns on eight LEDs sequentially Only one LED is on at a time therefore eight states exist Each state consists of one LED being turned on while all the rest are off State machines require a State Variable SV The SV is essentially a pointer that keeps track of the state that the microcontroller is in and directs the program flow to the corresponding software module The SV can be modified in the software modules or states themselves or by an outside function The example firmware uses an outside function which detects a button press to advance through the states 2 4 1 2 BENEFITS OF STATE MACHINES The introduction briefly mentioned some advantages of state machines These advantages are worth studying in greater detail because they are what make programmi
21. EECON1 RD read data movf EEDATA w return with LED sequence in w return As discussed in Tutorial 5 the returned value corresponds to an LED seguence This value is displayed using the Timer0 interrupt The LEDs are multiplexed fast enough to appear as though more than one LED is on at the same time When SWT is pressed an Interrupt on change is generated and the next LED sequence is read from the data memory Figure 2 15 shows the flowchart for this tutorial 2003 Microchip Technology Inc DS40051C page 37 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 15 DATA EE LOOK UP ROUTINES Initialize PIC12F6XX Load LEDREGISTER Is Button Pushed Retrieve Data from data memory update LEDs 2 8 3 Applications The look up routines presented herein are useful in applications that require the following 1 2 3 4 Storing and retrieving calibration values Maintaining current identification information Data logging information In general for any applications that require non volatile variable memory DS40051C page 38 2003 Microchip Technology Inc Tutorial Projects 2 8 4 Running The Demo 1 Program the dtlookup HEX file into the PIC microcontroller 2 After the HEX file is programmed into the device the LED array should show the first look up value in the 8 LED s To increment to the next look up value press SW1 See Table 2 3 TABLE 2 3 DATA TABLE CA I EEE O 2003
22. IG directive When using the PICkit 1 FLASH Starter Kits on board evaluation socket configure the internal oscillator The internal oscillator also frees up two more pins for general I O use The assembler directive to select the internal oscillator with all other functions off might look like this _CONFIG INTRC OSC NOCLKOUT amp WDT OFF amp BODEN OFF amp CP OFF amp CPD OFF The following code shows how to set the configuration bits in Hi Tech C _CONFIG UNPROTECT amp BOREN amp MCLRDIS amp PWRTEN WDTDIS amp INTIO 2 Are the pins multiplexed with other functions If so does the program initialize the control registers to select the function desired A common problem occurs on PORTA where the analog inputs to the ADC is multiplexed with digital functions The pins default to analog input For digital output write to the ANSEL register and make the pins digital I O 5 2 2 Device Will Not Program Question The device will not program All writes end with a checksum verified failed error message Answer 1 Are the code protect bits set in the source code file Currently the device can only be code protected by selecting the Tools gt Code Protect Device option in the PICkit 1 User s Interface 2 The part may be damaged Go to Microchip s web site www microchip com to request a new part O 2003 Microchip Technology Inc DS40051C page 55 PICkit 1 FLASH Starter Kit User s Guide 5 2 3 De
23. LDemoBoards PICki EB F MikeR D emoBoardsSFICKIM 24 Er Source Files Er Source Files i ledint azm hee edint asm EL Object Files E Object Files gt MtbE 5 0 x haa HHIDE S 0 Library Files gt Library Files ER Linker Scripts E Linker Scripts ee 121675 lkr n 125629 ler DS40051C page 28 O 2003 Microchip Technology Inc Tutorial Projects C Source Code e ledint c Main file that contains the main program and interrupt routine ledint h Header file e intlib675 0bj or intlib629 0bj Library file that contains the Display and Debounce functions for the PIC12F675 or PIC12F629 respectively FIGURE 2 8 MPLAB PROJECT SETUP C E ledint mcw IL x Es F HikeR DemoB Al El E F MikeR DemoBoards PICki El F AMikeR DemoBoards PICKIPSSL Source Files Er Source Files gt Object Files El Object Files ee intlibB75 obi e intlib523_obi gt Library Files 2 5 5 2 FILES REQUIRED FOR LIBRARY MODIFICATION Assembly Source Code e intlib asm Contains core Display and Debounce routines When assembled a intlib o file will be created C Source Code e intlib c Contains core Display and Debounce routines When compiled a intlib obj file will be created e intlib h Header file FIGURE 2 9 MPLAB PROJECT SETUP LIBRARY MODIFICATIONS E FAMikeRADemoboardsAPICKki 3 E F XMikeH yD emaHoardsxFICEi l Source Files l Source Files intlib asm Header Files Header Files
24. Microchip Technology Inc DS40051C page 39 PICkit 1 FLASH Starter Kit User s Guide 2 9 TUTORIAL 7 FREQUENCY COUNTING WITH TIMER1 GATE This program introduces the concept of auto calibration of the PIC12F6XX internal RC oscillator using a Known reference frequency The PIC12F6XX has an internal RC oscillator capable of being calibrated to 1 This tutorial covers the following e How to set up and use the Timer Gate peripheral e How to calibrate the PIC12F6XX internal RC oscillator e Useful applications that use the concepts presented in this tutorial e Files needed to customize source code for the application 2 9 1 Design This program takes advantage of the TIMER1 Gate Peripheral onboard the PIC12F6XX for auto calibration of the PIC12F6XX device 2 5 kHz reference signal is connected to pin GP4 Timer1 Gate input on the PIC12F6XX device The PIC12F6XX internal RC oscillator has the capability to run at 4 MHz 1 Using Timer1Gate is advantageous because it can eliminate busy waiting on the PIC microcontroller Using Timer1Gate allows the hardware to manage capturing of the reference signal low edge pulse width while allowing the PIC12F6XX to process other events for a given amount of time The time will depend on the period of the signal being measured In this case there is a 2 5 kHz reference signal This allows 400 us to go and process something else before we would need to read TIMER1 for a measurement 2 9 2 Im
25. Object Files ee intlib h Library Files Object Files Linker Scripts Library Files 2003 Microchip Technology Inc DS40051C page 29 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 10 HIGH LEVEL FLOWCHART Initialize PIC12F6XX HA Load LEDREGISTER Timer0 Overflow Interrupt GP3 Pin Change Interrupt Is Button Pushed Yes Change Flashing DS40051C page 30 2003 Microchip Technology Inc Tutorial Projects 2 6 TUTORIAL 4 ANALOG TO DIGITAL CONVERTERS AND COMPARATORS This tutorial is broken up into two programs which demonstrate how to use the analog to digital converter the comparator and the internal voltage reference The first program set is comp asm written in assembly and comp c written in C This program shows the very basic implementation of using the comparator with the internal voltage reference The second program set is atod asm written in assembly and atod c written in C This program uses the LED display library to show the value of the analog to digital A D converter 2 6 1 Comparator Tutorial For this tutorial the comparator is configured as a dedicated comparator driving the GP2 pin directly With lt CM2 CM0 gt 101 the comparator has multiplexed inputs GPO CIN is selected as the input to the VIN by setting CIS 1 thus making the analog potentiometer the one input The internal voltage reference is used as the other input to the comparator on
26. Programmer gt Erase from the toolbar menu as shown in Figure 1 8 FIGURE 1 8 DEVICE ERASE AN PICKit tm 1 FLASH Starter Kit File Programmer Tools About Pro Head Device LL hb Write Device Ruf Verity Full Erase eech amp BG erased Regenerate OSCCAL Set Bandgap Calibration Value 2003 Microchip Technology Inc DS40051C page 9 PICkit 1 FLASH Starter Kit User s Guide 1 6 6 1 FULL ERASE Unlike the Erase function the Full Erase allows the user to erase not only the device but the OSCCAL and Bandgap Calibration as well Performing a full erase is not recommended or needed in the normal course of events Only use this function if the OSCCAL or Bandgap data has been corrupted To perform a full erase select Programmer gt Full Erase OSCCAL amp BG erased from the toolbar menu as shown in Figure 1 8 Once the full erase is complete regenerate the OSCCAL and reset the Bandgap Calibration Value bits Note The Regenerate OSCCAL function runs a program on the device to recalculate the oscillator calibration value See Tutorial 7 Chapter 2 9 for more details To regenerate the OSCCAL select Programmer gt Regenerate OSCCAL from the toolbar menu as shown in Figure 1 9 FIGURE 1 9 REGENERATE OSCCAL AY PICKit tm 1 FLASH Starter Kit File Programmer Tools bout Read Device Ctri F Write Device L lou Werify Erase Full Erase OSECAL BG erased Regenerate OSCCAL Set Bandgap Calibrat
27. UPTS This program demonstrates how to use the Timer0 and pin change interrupts onboard the PIC12F6XX In addition the program illustrates how the PIC12F6XX is multiplexing the LED s fast enough to give the visual representation that the LED s are all on at the same time when in fact the LED s are lit individually Finally this program uses the interrupt on pin change to detect and debounce a button push which changes the rate at which the LED s are flashed This tutorial covers the following topics e How to flash LED s on the PICkit 1 FLASH Starter Kit board e How to use Timer0 and pin change interrupts on the PIC12F6XX e How to turn a source code file into a library file for easy reuse e Useful applications that can use the concepts presented in this tutorial e Files needed to customize the source code for the application 2 5 1 Design One of the challenges of using an 8 pin PIC microcontroller is having enough pins for a robust application The PICkit 1 FLASH Starter Kit utilizes design tips and tricks to get the most out of the 8 14 pin PIC microcontroller devices In particular a 12 LED array is implemented on the PICkit 1 FLASH Starter Kit by using only 4 pins In this tutorial only 8 LED s are implemented See Table 2 1 for LED multiplexing Also see TIP 2 Input Output Multiplexing in the Microchip Tips n Tricks booklet for more details on LED multiplexing TABLE 2 1 LED MULTIPLEXING TRUTH TABLE Pm po pt 02 0
28. VIN The module compares the potentiometer voltage with the reference and the logic is setup CINV 1 such that the output is high when the input voltage is higher than the reference LED3 is driven directly by the comparator and is lit when the output of the module is high To light D3 you must configure RA4 GPIO4 and RA2 GPIO2 as digital outputs via the TRIS register RA4 is set low and RA2 is driven directly by the comparator without additional software overhead The remaining I O s are configured as high impedance inputs Note The schematics as shown in Appendix A display the 14 pin device pinout This is compatible with 8 pin devices The internal voltage reference is essentially a variable resistor based voltage divider between VDD and Vss Use the low range mode VRR 1 and set the internal reference to be 0 5 VDD by selecting lt VR3 VRO gt 1100 thus CVREF VDD 12 24 By stepping through the different voltage reference settings a basic low resolution analog to digital converter can be implemented The comparator module has seven different modes Three of the modes can drive an output pin directly The software can monitor the output directly or create an interrupt on change Bits CMIE and PEIE must be set to enable the comparator interrupt which can be used to wake the device from SLEEP Figure 2 11 shows the project setup for the assembly and C projects FIGURE 2 11 ASSEMBLY AND C PROJECT SETUP ime C Projects
29. WM value is updated just over 500 times every second This ensures good voltage regulation of the 13V and leaves enough CPU time to perform the programming task The rest of the circuit is used to switch the VPP voltage to the VPP pin Transistor Q4 is the switch for the VPP voltage and Q3 is the driver for Q4 Transistor Q1 turns VDD on and off allowing the target device to be reset The programming I O signals are generated by bit banging RC6 7 of the PIC16C 745 which drives the GPIOO 1 lines used by the PIC12F629 675 2003 Microchip Technology Inc DS40051C page 51 PICkit 1 FLASH Starter Kit User s Guide PROGRAMMING HARDWARE FIGURE 4 1 H194S91 149 1VOdaS91 049 AASL Old ddA 10W7 d9 H19 dS9I MITO dS91 viva ae vivo aen Jn Q LO O3HOLIMS S A Sp ANN 318VN3 GGA LO 6l3 AG MOL An iQ AOL VO6ENC C ww 410 ddA GO ZZA co lt AR SE SE SE bla LLH FRS Sp 198903347 ddA SE SE E Lal Ola AGE o Set D en E anna aan 5 L L8SNL 4BDGENZ e e Je e TO q _ AQL anot O HN S9 Se UJI LI AG 29 41 9933 1Q xX 4 94 SVLZO9LOld ONv ova LNY LYH L JOO Z Oq 2003 Microchip Technology Inc DS40051C page 52 PICkit 1 FLASH Starter Kit Hardware 4 5 USB COMMUNICATIONS PROTOCOL The USB protocol used by the PICkit 1 FLASH Starter Kit
30. ab gt lt Ctrl C gt brackets lt gt Documents Arial font Italic characters Referenced books MPLAB IDE User s Guide Documentation Updates All documentation becomes dated and this user s guide is no exception Since the PICkit 1 FLASH Starter Kit User s Guide and other Microchip tools are constantly evolving to meet customer needs some PICkit 1 FLASH Starter Kit actual dialogs and or tool descriptions may differ from those in this document Please refer to our web site to obtain the latest documentation available Documentation Numbering Conventions Documents are numbered with a DS number The number is located on the bottom of each page in front of the page number The numbering convention for the DS Number Is DSXXXXXA where XXXXX The document number A The revision level of the document DS40051C page 2 2003 Microchip Technology Inc Preface WARRANTY REGISTRATION Please complete the enclosed Warranty Registration Card and mail it promptly sending in your Warranty Registration Card entitles you to receive new product updates Interim software releases are available at the Microchip web site RECOMMENDED READING This user s guide describes how to use the PICkit 1 FLASH Starter Kit Other useful documents are listed below PIC12F629 675 Data Sheet DS41190 Consult this document for information regarding the PIC12F629 675 8 pin FLASH based 8 bit CMOS Microcontroller device specificati
31. and PCLATH when PCL overflows If a provision of increment PCLATH is not included then there is a risk of jumping to the wrong spot in the program if PCL overflows Immediately following the increment routine is a list of goto statements that direct the program flow to one of the states This method is called a computed goto The following example code shows how to use a computed goto for a state machine DS40051C page 24 2003 Microchip Technology Inc Tutorial Projects EKAMPLE 2 2 COMPUTED GOTO Initialize clrf initialize state machine Main call StateMachine goto Main StateMachine movlw high StateTable set high order byte of program movw PCLATH counter appropriately movf STATE W mask state variable to keep andlw 03h things under control addlw low StateTable add state variable to ROM address btfsc STATUS C beginning State Table incf PCLATH F overflows yes increment PCLATH movw PCL move computed goto value into PC StateTable goto Stated goto Statel goto State2 goto State3 State0 incf goto the next state return Statel return O 2003 Microchip Technology Inc DS40051C page 25 PICkit 1 FLASH Starter Kit User s Guide 2 4 3 Implementing this Demo The flowchart for this demo is shown in Figure 2 6 However the flowchart does not show the debounce routine implemented in ButtonPress The debounce routine is based on the Brute Force Debounce described in Tuto
32. controllers e Program the 8 14 pin FLASH PIC microcontrollers e Operate from a USB cable 42 HIGHLIGHTS This chapter discusses e ICSP Techniques e Programming Hardware e USB Communications Protocol 43 IN CIRCUIT SERIAL PROGRAMMING ICSP TECHNIQUES ICSP allows an engineer to design a circuit that will be built and then programmed later The procedure is described in the programming specifications DS41173 and DS41191 These documents can be found on the Microchip web site http www microchip com ICSP requires a 12 13V power supply control of the VDD supply and two l O pins to clock in the commands and data 44 PROGRAMMING HARDWARE The programmer portion of the PICkit 1 FLASH Starter Kit circuit is shown in Figure 4 1 Additional circuitry is present to connect to the USB and drive the evaluation LED s Most of the circuitry in the figure is used to generate the 13V required for VPP This is generated by using the CCP of the PIC16C745 to pulse Q2 on and off By pulsing Q2 L1 generates a burst of charge that is steered into the capacitor C4 by the diode D13 Each burst of charge adds to the voltage already in the capacitor The size of the burst of charge is proportional to the on time of the PWM signal from CCP The resistors R10 and R11 form a voltage divider that drops the 13V VPP to a 4 5V feedback signal that is measured by ANT Software running in the PIC16C745 periodically samples AN1 and computes a new PWM value The P
33. e of the lights will change If the variable resistor labeled RP1 is turned the light sequence will blink at a different rate 1 5 HEX FILES The PICkit 1 FLASH Starter Kit CD ROM includes tutorial HEX files and source code to use in conjunction with the program tutorials in Chapter 2 The HEX files are a binary form of instructions executed on the PIC microcontroller They are generated when the source files are built in MPLAB IDE 2003 Microchip Technology Inc DS40051C page 5 PICkit 1 FLASH Starter Kit User s Guide 1 6 USING THE PICkit 1 FLASH STARTER KIT PROGRAMMING INTERFACE Execute the software by selecting Start gt Programs gt PICkit tm 1 FLASH Starter Kit The programming interface appears as shown in Figure 1 1 FIGURE 1 1 PICkit 1 FLASH STARTER KIT PROGRAMMING INTERFACE 8 PICkit tm 1 FLASH Starter Kit File Programmer Tools About Program Memory 3FFF 3FFF SERE JEFE 3FFF 3FFF 3FFF 3FFF 3FFE 3FFF SERE SEE JEFE EEE Board Controls MW Device Power 25 kHz sc El Write Device Verify Erase Quit Device Configuration Device PICT 2F6 5 Configuration Word Ox3FFF User Ds Os fFeF FF FF USCCAL Os SFFF CheckSum OxBEOO Bandgap 02000 Firmware Version 0 3 0 Notice that the Device Power check box is selected This is a default function indicating the device power is turned on Note To turn the device power off d
34. e window will show the instruction that will be executed next as shown in Figure 3 5 FIGURE 3 5 CODE WINDOW ERRATA a YW KW NW WW WW W W 0 WW WY WY W YW W ORG OxOO0 Processor reset vector S nop r Inserted For ICDZ Use goto Init r go to beginning of program r kO YW 8 W OW W Y W W 9 W K W W W 9 W W W W W 9 0 W W W W 9 W W 9 W W W T W W W W Y W W 9 0 W W W W W W W 9 W W 9 0 8 W W W W T W 9 W W W T W 9 T W Y 2003 Microchip Technology Inc DS40051C page 49 PICkit 1 FLASH Starter Kit User s Guide In the View toolbar menu there are options to view the special function registers program memory and other useful information as shown in Figure 3 6 FIGURE 3 6 VIEW MENU OPTIONS ss MPLAB IDE File Edit View Project Debugger Programmer Project Output Watch Hardware Stack Program Memor File Registers EEPROM Di Fire Special Function Registers Simulator Trace To learn more about using MPLAB IDE please refer to the MPLAB IDE User s Guide found on the MPLAB IDE CD ROM included in the PICkit 1 FLASH Starter Kit DS40051C page 50 2003 Microchip Technology Inc PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Chapter 4 PICkit 1 FLASH Starter Kit Hardware 41 INTRODUCTION The PICkit 1 FLASH Starter Kit hardware was designed to be a low cost introductory programmer and evaluation kit The requirements of the hardware are as follows e Support the 8 14 pin FLASH PIC micro
35. echnical Support 480 792 7627 Web Address http www microchip com Rocky Mountain 2355 West Chandler Blvd Chandler AZ 85224 6199 Tel 480 792 7966 Fax 480 792 4338 Atlanta 3780 Mansell Road Suite 130 Alpharetta GA 30022 Tel 770 640 0034 Fax 770 640 0307 Boston 2 Lan Drive Suite 120 Westford MA 01886 Tel 978 692 3848 Fax 978 692 3821 Chicago 333 Pierce Road Suite 180 Itasca IL 60143 Tel 630 285 0071 Fax 630 285 0075 Dallas 4570 Westgrove Drive Suite 160 Addison TX 75001 Tel 972 818 7423 Fax 972 818 2924 Detroit Tri Atria Office Building 32255 Northwestern Highway Suite 190 Farmington Hills MI 48334 Tel 248 538 2250 Fax 248 538 2260 Kokomo 2767 S Albright Road Kokomo Indiana 46902 Tel 765 864 8360 Fax 765 864 8387 Los Angeles 18201 Von Karman Suite 1090 Irvine CA 92612 Tel 949 263 1888 Fax 949 263 1338 San Jose Microchip Technology Inc 2107 North First Street Suite 590 San Jose CA 95131 Tel 408 436 7950 Fax 408 436 7955 Toronto 6285 Northam Drive Suite 108 Mississauga Ontario L4V 1X5 Canada Tel 905 673 0699 Fax 905 673 6509 ASIA PACIFIC Australia Microchip Technology Australia Pty Ltd Marketing Support Division Suite 22 41 Rawson Street Epping 2121 NSW Australia Tel 61 2 9868 6733 Fax 61 2 9868 6755 China Beijing Microchip Technology Consulting Shanghai Co Ltd Beijing Liaison Office Unit 915 Bei Hai Wan Tai B
36. eselect the check box DS40051C page 6 2003 Microchip Technology Inc Using the PICkit 1 FLASH Starter Kit 1 6 1 Download Project from MPLAB To download a compiled program to the PICkit 1 FLASH Starter Kit select File gt Import HEX as shown in Figure 1 2 Browse for the HEX file and click Open FIGURE 1 2 IMPORT HEX FILE AN PICKit tm 1 FLASH Starter Kit File Programmer Tools About Export HES Ctri E 3FFF A FFF Exit Cl 3FFF 3FFF 0020 3FFF 3FFF 3FFF MAA AFFF 4FFF 3FFF The code is displayed in the Program Memory and EEDATA Memory windows For more information on Program and EEDATA memory see Tutorial 5 Chapter 2 7 and Tutorial 6 Chapter 2 8 After the HEX file is imported write the program to the device by clicking the Write Device button The existing program will be erased and replaced with the new one The status of the program write is displayed in the status bar located at the bottom of the interface window If the write is successful the status bar turns green and displays write successful as shown in Figure 1 3 FIGURE 1 3 WRITE SUCCESSFUL STATUS BAR Read Device Verify Erase Quit Device Configuration Device PICT 2F675 Configuration Word DOx3FC4 User Ds Ox F fF YF FF OSCCAL Ox SFFF CheckSum COe44 Bandgap Oe 000 If the write fails the status bar turns red and displays checksum verify failed as shown in Figure 1 4 This error indicates the data was corrupted
37. formation Line Numbers are 1 800 755 2345 for U S and most of Canada 1 480 792 7302 for the rest of the world DS40051C page 4 O 2003 Microchip Technology Inc PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Chapter 1 Using the PICkit 1 FLASH Starter Kit 1 1 INTRODUCTION The PICkit 1 FLASH Starter Kit serves as a development and evaluation tool for the 8 14 pin FLASH PIC microcontroller devices 1 2 HIGHLIGHTS This chapter discusses e The PICkit 1 FLASH Starter Kit Contents e Running the PICkit 1 FLASH Starter Kit Default Demonstration e Pre loaded HEX files e Using the PICkit 1 FLASH Starter Kit Programming Software 1 3 PICkit 1 FLASH STARTER KIT CONTENTS The PICkit 1 FLASH Starter Kit contains the following items The PICkit 1 FLASH Starter Kit Printed Circuit Board PCB USB cable PICkit 1 FLASH Starter Kit CD ROM MPLAB IDE CD ROM Microchip Tips n Tricks booklet PICkit 1 FLASH Starter Kit USB Installation for Windows 98 Second Edition Use the Quick Start Guide to install the PICkit 1 FLASH Starter Kit and MPLAB IDE software DOS NS 14 RUNNING THE PICkit 1 FLASH STARTER KIT DEFAULT DEMONSTRATION Connect the PICkit 1 FLASH Starter Kit board to the PC s USB port using the USB cable The pre loaded demonstration program is displayed on the board The demo program will blink the eight red lights in succession Press the button labeled SW1 on the board and the sequenc
38. gdom Microchip Ltd 505 Eskdale Road Winnersh Triangle Wokingham Berkshire England RG41 5TU Tel 44 118 921 5869 Fax 44 118 921 5820 02 12 03 DS40051C page 68 O 2003 Microchip Technology Inc
39. he check box next to Microsoft Windows Update and click Next Windows will automatically install the appropriate driver Do not use the ICD 2 USB driver 5 2 6 Editing Device Memory Question When using the PICkit 1 User s Interface to edit the actual contents of the memory It will not allow date selection Why not Answer The PICkit 1 User s Interface was developed to program a device It was not intended to edit the contents of a device Please use MPLAB to edit the contents of the device The data in the window can be selected to cut and paste the date into another editor for use in other applications 5 2 7 No Source Code Question After moving the tutorial data files to a different location on the hard drive the MPLAB simulator behaves strangely When stepping through the code a program memory window is displayed without the source code What is wrong Answer The MPLAB version 6 13 and earlier simulator does not support source level debugging when the path to the source code is gt 64 characters long Moving the data files to a location with a shorter path name will fix the problem This will be fixed in a future version of the MPLAB software 5 2 8 HI TECH PICC LITE Question Why does the default demonstration code not work correctly after compiling with the HI TECH PICC LITE Compiler Answer Download the latest HI TECH PICC LITE C Compiler from the HI TECH web site www htsoft com 2003 Microc
40. he firmware easier to debug When a bug is encountered set a break point at the jump station Then step through the program state by state until the bug is found An example of a bug would be the SV being modified incorrectly in one of the states If this happens the wrong state will be called the next time the program flow returns to the jump station However because the SV is being monitored it will be very easy to see when an unintentional change is made to the SV and in which state the SV was incorrectly modified Note MPLAB IDE contains a built in simulator See the MPLAB IDE v6 xx Quick Start Guide available on the MPLAB IDE CD ROM included with the PICkit 1 FLASH Starter Kit Another benefit of state machines is firmware that incorporates state machines naturally promotes modular code Modular code has its own list of benefits 1 Upgrades and special features can be easily added to the code in later revisions or as a product evolves 2 Modules can be cut and pasted into other applications quickly and easily 3 Other developers will be able to understand the code in order to support it The jump station if commented well can be an index to each of the software modules 2 4 2 Implementation 2 4 2 1 GENERAL THOUGHT PROCESS When implementing a FSM first brainstorm all the states needed to complete a particular application Once this is done identify the first state Next the following question should be answered Wha
41. hip Technology Inc DS40051C page 57 PICkit 1 FLASH Starter Kit User s Guide NOTES DS40051C page 58 O 2003 Microchip Technology Inc AN PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Appendix A Hardware Schematics A 1 INTRODUCTION This appendix contains the PICkit 1 hardware schematic diagrams A 2 HIGHLIGHTS The diagrams in this appendix are e PICkit 1 Board Diagram e LED Layout e VPP Supply e USB Control e Prototype 1 e Prototype 2 2003 Microchip Technology Inc DS40051C page 59 PICkit 1 FLASH Starter Kit User s Guide PICkit 1 BOARD DIAGRAM FIGURE A 1 9 JO L jesus Le CAS LUMO uupu j NOLYOJ d Aq umbu Cppz CL L 3300 00L LOTTO JequnN LIM Y318V1S HSV14 L Old HOS am MN G3HOLIMS S C Lee d AL 190001 1 CA wae SS LIBSNI Joi YI Je ddA lt Ova CVA LO E FM NO y AE Loy In Wa O3HOLIMS S 147920S NOILVN TWAS 031V1Nd0d INV 03134905 auv 0 HLM 03139V1 SN31 d31WINdO4 LON Juv LO 1N8 03134905 auv g HLIM 3138V1 SW3LI G3LVINdOdNN 39 y HUM 03138V1 SWALI d20WIIN WU NM 3H1 NOYW 431110 AVW ONY AINO 39N343134 403 Juv 3J3H NMOHS SYJ WNN X S3NVN JOAO N8 JYV SYOLSISSY 3ONV43101 ZG SUV SYUOLSISIY AN NI JYV SANIVA SONVLIOVdVO SNHO NI 33V SANTWA SONVLSISSY OD 3SIMY3HLO SSTINN SALON A AVN 3I8VN3 GOA e RO 613
42. ift registers see Figure 2 1 and Figure 2 2 These methods are still effective but they involve additional cost in material installation and board real estate Why suffer the additional expense when software is free and program memory is abundant 2003 Microchip Technology Inc DS40051C page 13 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 1 FILTERING DEBOUNCE SOLUTION Filtered Switch Output FIGURE 2 2 SHIFT REGISTER DEBOUNCE SOLUTION Debounce Clock DS40051C page 14 O 2003 Microchip Technology Inc Tutorial Projects 2 3 1 Design Switch bounce is intermittent contact and release of the switch contacts Two parameters characterize switch bounce bounce period and bounce duration Bounce period is the random length of time the contacts remain open or closed while the bounce is occurring Bounce periods can vary anywhere from a few nanoseconds to a few milliseconds Bounce duration is the time from the leading edge of the first bounce period to the trailing edge of the last bounce period The difficulty is bounce duration is indeterminate Bounce abatement design starts by making assumptions based on empirical data The first assumption is bounce period will be absolutely less than 10 milliseconds Experience dictates this is a good assumption however bench and field testing are still essential to ensure the switch selected for the application does not have a longer bounce period The second a
43. ion Value To set the Bandgap Calibration Value select Programmer gt Set Bandgap Calibration Value from the toolbar menu as shown in Figure 1 10 FIGURE 1 10 REGENERATE BANDGAP CALIBRATION VALUE AY PICkit tm 1 FLASH Starter Kit File Programmer Toole About Read Device Ctri F Write Device Ctrl Verity Erase Full Erase OSCOAL amp BG erased Regenerate UG Cal Set Bandgap Calibration Value DS40051C page 10 2003 Microchip Technology Inc Using the PICkit 1 FLASH Starter Kit The Write Bandgap Calibration Value window will appear as shown in Figure 1 11 Select a bit value from the list and click OK FIGURE 1 11 SELECT BANDGAP BIT VALUE w Write Bandgap Calibration Value EX Select Bandgap Value Warning This function will erase the device OSCECAL will be preserved The Bandgap setting affects BUR and POR trip voltaqes Bit Value C 040000 OOK 1000 Canes C 0x3000 The Bandgap bit value will appear in the Device Configuration box as shown in Figure 1 12 FIGURE 1 12 DEVICE CONFIGURATION Device Configuration Device PICT 2F6 FE Configuration Word Ds3FFF User Ds REF OSCCAL Ox SF FF CheckSum OxBEOO Bandgap 02000 For more information on the OSCCAL and Bandgap Calibration see the PIC12F629 675 DS41190 and PIC16F630 676 DS40039 Data Sheets located on the CD or the Microchip web site www microchip com 1 6 7 2 5 kHz OSC The 2 5 kHz OSC is a square
44. is a very simple command response type protocol Multiple commands can be put together to fill the 8 bytes of a USB packet If a command cannot fill the 8 bytes and it is not desired to use a second command to fill the packet the packet should be padded with Z to indicate no operation 4 5 1 Commands e W lt word gt Write Program Memory Loads the write latch sends the write command and increments to the next address C lt word gt Configuration memory write mode Word parameter ignored Use W to write to configuration memory D lt byte gt Write EE Data memory Data is passed as the byte E Bulk Erase Program Memory e Bulk Erase Data Memory T lt word gt Increment Address N times N is passed as word P Enter programming mode Turns VPP and VDD on p Exit Programming Mode Turns VDD and VPP off R Read Program Memory R always returns 4 words If the end of PGM memory is reached it pads with O s It is the responsibility of the host software to determine if padding occurred by keeping track of the program counter r Read EE Data Memory r always returns 8 bytes If the end of Data memory is reached it pads with 0 s It is the responsibility of the host software to determine if padding occurred by keeping track of the program counter S lt program memory length data memory length gt Calculates Program Memory Checksum and
45. ity including a stable button pushed state resets the debounce 10 millisecond timer 2003 Microchip Technology Inc DS40051C page 15 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 3 BRUTE FORCE SWITCH DEBOUNCE Debounce Initialize Switch Closed Set Timer Count For 10 ms Switch Closed Decrement Timer Counter DS40051C page 16 O 2003 Microchip Technology Inc Tutorial Projects 2 3 1 2 SWITCH FILTER DEBOUNCE There are situations when both stable switch states must be recognized It is undesirable for immediate action to occur if the switch intermittently leaves either the pushed or released state A door open or closed sensor switch is a good example of this If the door is closed and gets bumped then the door open action such as an alarm should not occur because the door is still closed The Switch Filter debounce method delays the response to a changed switch state Delay time can even be extended to several times the bounce period Switch Filter debounce incorporates a saturating up down counter A saturating counter is one that stops counting when the maximum or minimum number is reached The counter counts up when the switch is closed and counts down when the switch is open The appropriate action is invoked when the counter reaches either the full up or down count Hysteresis is built into the count length Switch release or contact action is invoked only upon the first occ
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47. le code would look like if a state machine where not used Compared to Figure 2 6 which shows a block diagram of state machine based code it is clear that using a state machine cuts down on code space and the likelihood of missing a repetitive task call DS40051C page 20 2003 Microchip Technology Inc Tutorial Projects FIGURE 2 5 STATE MACHINE NOT USED Initialize Routine N Clear WDT Clear WDT es Yes T T ButtonPress GE Ge ButtonPress gi Se Clear WDT Clear WDT es Yes Turn only Turn only ButtonPress LED1 on ButtonPress LED5 on N Clear WDT Clear WDT es Yes Turn only Turn only ButtonPress LED2 on ButtonPress LED6 on Clear WDT Clear WDT ig es Yes ButtonPress o ny o es 2003 Microchip Technology Inc DS40051C page 21 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 6 STATE MACHINE BASED CODE Initialize Routine Clear WDT ButtonPress 21 Yes Increment State Variable 4 Turn only Turn only Turn only Turn only LEDO on LED2 on LED4 on LED6 on Turn only Turn only Turn only Turn only LED1 on LED3 on LED5 on LED7 on Note 1 ButtonPress detects when Switch 1 is pressed This function also implements a debounce routine not shown See Section 2 4 2 Implementation for details DS40051C page 22 2003 Microchip Technology Inc Tutorial Projects The fact that the state machine based firmware always returns to the same point in the code also makes t
48. lexed fast enough that the human eye can not detect the LEDs being turned on and off When SW is pressed an interrupt on change is generated to increment the lookup to the next location Figure 2 14 shows the flowchart for this example DS40051C page 34 O 2003 Microchip Technology Inc Tutorial Projects FIGURE 2 14 PROGRAM MEMORY LOOK UP TABLE PROCESS Initialize PIC12F6XX Load LEDREGISTER Is Button Pushed Retrieve Data from Program memory update LEDs 2 7 2 Applications The lookup routines presented herein are useful in applications that require the following 1 2 3 4 Retrieving calibration values Retrieving serial numbers Retrieving LED seguences Retrieving constants or strings in general that will not change over the lifetime of the PIC microcontroller 2003 Microchip Technology Inc DS40051C page 35 PICkit 1 FLASH Starter Kit User s Guide 2 7 3 Running The Demo 1 Program the pglookup hex code to the PIC microcontroller 2 After the HEX file is programmed to the device the LED array should show the first look up value in the 8 LEDs To increment to the next look up value press SW1 See Table 2 2 TABLE 2 2 DATA TABLE DS40051C page 36 2003 Microchip Technology Inc Tutorial Projects 2 8 TUTORIAL 6 DATA EE LOOK UP ROUTINES 2 8 1 Introduction Tutorial 5 discussed storing and retrieving constants from program memory The benefit of storing infor
49. mation in non volatile program memory is when power is cycled to the microcontroller the information is not lost However the main disadvantage is information stored in program memory can not change RAM on the other hand offers the versatility of change but is volatile it is cleared when power is cycled to the microcontroller Data EEPROM solves this problem by providing non volatile readable writable memory An added benefit of Data EEPROM is a developer can free up valuable RAM by using data memory to store rarely accessed variables This tutorial covers the following topics e How to implement Data EEPROM look up routines e Why Data EEPROM look up routines are useful 2 8 2 Design The PIC12F629 675 DS41190 and PIC16F630 676 DS40039 data sheets provide detailed instructions on how to access data memory See the data sheets for timing specifications and limitations to the data memory The data sheets are located on this CD and the Microchip web site www microchip com The steps for reading the Data EEPROM are as follows 1 Write the data memory location to the EEADR register 2 Set EEPROM control bit RD EECON1 lt 0 gt All data memory locations can be accessed using a single routine when an index variable is utilized Example 2 4 shows how to use an index variable to read the Data Memory EXAMPLE 2 4 INDEX VARIABLE LookupDEE mov index w move data memory address pointer banksel EEADR to EEADR movw EEADR bsf
50. nce hex Select this file and click the Open button Note The Program Memory window displays the program code 4 Click the Write Device button The status of the program write is displayed in the status bar located at the bottom of the interface window 5 Torun the demo push the SW1 switch on the board and observe that LED DO toggles as expected 2 3 3 2 SWCHFLTR DEMO SwchF itr is an abbreviation for the Switch Filter debounce demo In this demo LED Di lights up when SWT is pushed When SWT is released LED DO lights up Repeat steps 1 through 5 above and load the SwchFltr hex file to run this demo 2 3 3 3 DBNCFLTR DEMO DbncFltr is an abbreviation for Debounce Filter This demo is a combination of the Debounce and Switch Filter demos DbncFltr also demonstrates timed expansion of switch functions This demo initializes in the Switch Filter mode Holding the button down for more than 1 second while in the Switch Filter mode causes the demo to change to the Brute Force method LED DO will light as an indication of the change Holding the button down for more than 1 second while in the Brute Force mode causes the demo to change to the Switch Filter method LED D1 will light as an indication of the change Repeat steps 1 through 5 above and load the DbncFltr hex file to run this demo 2003 Microchip Technology Inc DS40051C page 19 PICkit 1 FLASH Starter Kit User s Guide 2 4 TUTORIAL 2 INTRODUCTION TO ST
51. ng with state machines so rewarding and beneficial to firmware developers The first advantage is using state machines inherently promotes good firmware design techniques When beginning to implement an application think about what states are necessary to make the application work List all the pieces or states of an application and then explore how they tie to one another This will help prevent developing bugs in the code This line of thinking also leads to the development of a very useful engineering tool the flow chart The following paragraph covers state machine development in greater detail State machines have one characteristic that cause them to be very beneficial They always return to one spot or jump station in the code at which the program flow is channeled by the state variable to the corresponding software module This provides several advantages First this characteristic makes calling repetitive tasks on a regular basis quite simple Clearing the watchdog timer checking for I O button presses or communicating with a host that requires periodic communication are examples of repetitive tasks The alternative to using state machines is to use looping code In order for looping code to handle repetitive tasks the functions that handle these tasks must be distributed throughout the code in each of the loops This is not only highly inefficient but also confusing to understand Figure 2 5 shows a block diagram of what the examp
52. of all mechanical switches This includes push buttons of all types limit switches of all types and even X Y matrix keyboards Matrix keyboards offer a new challenge to debouncing Keyboards are not a single line input level but a pattern on several inputs One pattern represents all keys released or the stable state All other patterns represent keys pressed or the unstable states Reliable keyboards can be designed by debouncing to only the stable state but allowing new actions to occur immediately upon a change from one unstable state to another The solution is left to the interested student 2 3 3 Running the Demos There are three switch debounce demos Debounce SwchFltr and DbncHltr The file name suffix denotes the source code language for each demo The suffix asm denotes assembly language The suffix c denotes C language Use the Intel 32 bit HEX file output as the input file to the PICkit 1 FLASH Starter Kit demo board Intel HEX files are denoted by the hex file suffix 2 3 3 1 DEBOUNCE DEMO Debounce is the Brute Force debounce demo Each button push in this demo causes LED DO to toggle on or off Perform the following steps to run the Debounce demo 1 Connect the USB cable to the USB PC port and to the PICkit 1 FLASH Starter Kit demo board 2 Execute the PICkit 1 FLASH Starter Kit programming software 3 From the toolbar menu select File gt Import Hex Browse to locate the HEX file named Debou
53. ogram memory look up table is e How a program memory look up table is implemented e Why a program memory look up table is useful 2 7 1 Design Constants stored in program memory are accessed via look up tables A look up table is similar to a computed goto see Tutorial 2 Section 2 4 only instead of a list of goto statements after incrementing the program counter there is a list of ret 1w instructions Each ret 1w instruction is followed by one byte of the information Example 2 3 shows a look up table for the string Microchip written in assembly language EXAMPLE 2 3 LOOK UP TABLE WRITTEN IN ASSEMBLY LookupProgramMemory movlw movwt movlw addwf btfsc incf movwf high StartTable PCLATH low StartTable index w STATUS C PCLATH f PCL StartTable retlw retlw ach reblw PE retlw WA retlw oll Feb E retlw mJy retlw Nai retiw p M For this tutorial constants corresponding to a sequence of LEDs are stored in a program memory look up table For instance the first constant stored is 5F This corresponds to the binary number 01011111 Each bit corresponds to an LED therefore LEDs DO D1 D2 D3 D4 and D6 will be lit when this constant is accessed After each look up table the value is displayed on the LEDs in the same fashion as discussed in Tutorial 3 Section 2 5 using the TimerO interrupt The appearance of more than one LED being lit at a time is possible because the LEDs are multip
54. ons PIC16F630 676 Data Sheet DS40039 Consult this document for information regarding the PIC16F630 676 14 pin FLASH based 8 bit CMOS Microcontroller device specifications MPLAB IDE User s Guide DS51025 Consult this document for more information pertaining to the installation and features of the MPLAB Integrated Development Environment IDE Software To obtain these documents contact the nearest Microchip sales location see back page These documents are also available on the Microchip web site at www microchip com Microsoft Windows Manuals This manual assumes that users are familiar with the Microsoft Windows operating system Many excellent references exist for this software program and should be consulted for general operation of Windows TROUBLESHOOTING see Chapter 5 for information on common problems MICROCHIP ON LINE SUPPORT Microchip provides on line support on the Microchip web site at http www microchip com A file transfer site is also available by using an FTP service connecting to ftp ftp microchip com The web site and file transfer site provide a variety of services Users may download files for the latest development tools data sheets application notes user guides articles and sample programs A variety of Microchip specific business information is also available including listings of Microchip sales offices and distributors Other information available on the web site includes
55. plementation In this program GPO is used to output a test signal If the PIC12F6XX internal RC oscillator is calibrated the test signal will be a 5 kHz square wave In addition the program uses the GP3 push button input to select calibration mode To turn on the 2 5 kHz fixed frequency source select the box from the Board Controls area in the PICkit 1 FLASH Starter Kit control panel See Figure 2 19 through Figure 2 22 for program flowcharts 2 9 3 Applications This program could be useful in the following applications 1 High volume production environment 2 Battery applications could use on board calibration to recalibrate the internal RC oscillator as the battery voltage drops 3 Applications that are exposed to a varying voltage and temperature ranges could have intelligent on board recalibration DS40051C page 40 2003 Microchip Technology Inc Tutorial Projects 2 9 4 1 Program the autocal hex code to the PIC12F6XX PIC microcontroller 2 Once the device is programmed LED D6 turns on indicating test mode 3 Check the device calibration by connecting an oscilloscope probe or frequency counter to GPO and compare the measurement to 5 kHz 4 To calibrate the device select the 2 5 kHz Osc checkbox and turn on the 2 5 kHz reference signal in the Board Controls frame as shown in Figure 2 16 Press the SW1 button on the PICkit 1 FLASH Starter Kit board LED D7 will turn on when the button is pushed this indicate
56. rial 1 Section 2 3 with one slight modification the debounce routine is implemented as a state machine The Debounce state machine differs from the LED state machine where the states themselves modify the state variable Implementing the debounce routine as a state machine is easier to understand than implementing it as looping code 2 4 3 1 APPLICATIONS As mentioned earlier in Section 2 4 1 2 state machines are useful in nearly every application The LED library in subsequent tutorials utilizes state machines to light the LED similarly to the state machine implemented in this tutorial State machines are useful for bit banging any number of communication protocols receiving RF transmissions controlling the speed of a motor the list goes on and on Understanding the states necessary to make the application work is a good way to begin implementing an application 2 4 3 2 RUNNING THE DEMO 1 Program the state hex code into the PIC12F629 PIC microcontroller using the PICkit 1 FLASH Starter Kit board and programming interface 2 Ifthe part is programmed successfully The DO LED will light up Press the SW1 switch located on the board to sequence through the state machine The D1 LED will light up then the D2 and so on 2 4 3 3 FILES REQUIRED FOR PROGRAM MODIFICATION Assembly e state asm HI TECH C state c state h DS40051C page 26 2003 Microchip Technology Inc Tutorial Projects 2 5 TUTORIAL 3 INTERR
57. routine and functions e autocal h Header File e delay obj HI TECH PICC Lite supplied delay function Source code is located in C Picclite samples delay FIGURE 2 18 MPLAB PROJECT SETUP G E Mike Demoboards PICKI FL l Source Files o autocalc El Header Files autocalh l Object Files delay aby Library Files DS40051C page 42 2003 Microchip Technology Inc Tutorial Projects FIGURE 2 19 MAIN FLOW Retrieve Factory Calibration Value Is Calibrate Call Button CALIBRATE Pressed CALL TEST FIGURE 2 20 TEST FLOW Has a Update OSCCAL Calibration Register with Been EEPROM Performed Calibration Value Output 5 kHz 50 Square Wave Is Calibration Button Pushed 2003 Microchip Technology Inc DS40051C page 43 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 21 CALIBRATE FLOW START CALIBRATE Reset Calibration Counter Measure 200 us PW Check If The Measured PW Is Within The Specified Tolerance See Figure 2 22 Decrement Calibration Counter Is Calibration Counter 0 Yes Update EEPROM Flag and Calibration Value END CALIBRATE PW Pulse Width DS40051C page 44 2003 Microchip Technology Inc Tutorial Projects FIGURE 2 22 CHECKPW W FLOW START CHECKPW W Is The Measured PW 200 us Is The Measured PW Is The Measured PW Within The Tolerance lt 200 us No Is The Measured PW AUST oe ep
58. s bar turns red and displays the error Verify Failed Error in program memory as shown in Figure 1 6 FIGURE 1 6 CODE ERROR STATUS BAR Head Device Write Device u Device Configuration Device FIC12F675 Configuration Word x3FL4 User IDs NEE OSCCAL s3FFF Checksum 0xC044 Bandgap On 000 1 6 4 Read Device To view the code written to the device click Read Device The code is displayed in the Program and EEDATA Memory windows for your review DS40051C page 8 2003 Microchip Technology Inc Using the PICkit 1 FLASH Starter Kit 1 6 5 Code Protect This function enables the code protection features of the device To protect the code complete the following steps 1 Import the HEX file 2 Select Tools gt Code Protect Device as shown in Figure 1 7 3 Click Write Device FIGURE 1 7 CODE PROTECT AYPICKit tm 1 FLASH Starter Kit File Programmer Tools About Program Hemor wW Code Protect Device 0000 w Toggle Device Power J0CF OLAS 2 6 kHz Use 2930 2913 1055 2523 D8AD 1903 0008 UBAO Note Ifthe device is read after it has been code protected the Program and EEDATA Memory windows will display all zeros 1 6 6 Erase The Erase function erases code from the device However this function is not normally needed since the Write Device function performs an erase prior to writing code to the device To erase the device using the Erase function click the Erase button or select
59. s calibration mode 5 View the test signal output on GPO using the oscilloscope or frequency counter and compare the measurements to the previous one before performing a calibration The measurement will be within 1 of 5 kHz Running The Demo FIGURE 2 16 PICkit 1 FLASH STARTER KIT PROGRAMMING INTERFACE AY PICKit 1 FLASH Starter Kit File Programmer Tools About Program Memory 0503 080E OS E 080E 080E 1283 1303 UGUC 1003 1653 1105 3007 2068 0821 0183 3920 3908 3910 3940 UGUC 2530 3906 2857 3901 1283 D S 2068 UU 3 0041 1903 1903 1903 1903 1583 1283 1903 Ds ok 1003 2066 1283 2068 DEAD Board Controls M Device Power Head Device Write Device Verity Erase Quit Device Configuration Device PICT ZE Zb User Ds DszFZFzZF7F CheckSum WDsa28B3 Firmware Version 0 1 5 Configuration Word 00184 Usclal UN 3404 BandG ap 00000 O 2003 Microchip Technology Inc DS40051C page 41 PICkit 1 FLASH Starter Kit User s Guide 2 9 5 Modifying The Source Code 2 9 5 1 REQUIRED FILES FOR PROGRAM MODIFICATION Assembly Code e autocal asm This is the only file needed to build the project FIGURE 2 17 MPLAB PROJECT SETUP ASSEMBLY E FAMikeRADemoBoardsPICKki PME Source Files i autocalasm Header Files Object Files Library Files Linker Scripts C Code e autocal c This is the main file which contains the main program interrupt
60. ssumption is the total bounce duration is indeterminate A good design should work regardless of how long the switch bounces provided that it eventually does stop bouncing 2 3 1 1 BRUTE FORCE DEBOUNCE Consider a simple push button application In this case some event should occur when a button is pushed Ideally the invoked event will occur immediately and only once for each button push The system should be also ready to respond to a repeat button push as soon as possible after the button is released This presents an apparent dilemma How is the difference between switch bounce and repeated button pushes determined Recall the assumption that the bounce period is less than 10 milliseconds If the switch input level is stable for longer than 10 milliseconds then bouncing has stopped and the input level represents the pushed or released switch state The Brute Force method only cares about a button push event because this is what invokes the action It recognizes the switch release state as the stable state and everything else is considered unstable When the switch becomes unstable the action is invoked permitting nothing to happen until the switch returns to the released stable state The flowchart in Figure 2 3 outlines the software actions necessary to implement the Brute Force debounce method Notice that the debounce loop is looking for a stable released state for 10 milliseconds before returning to the top of the main loop Any instabil
61. t Debugger Programmer Configure Window Help Hew osa pen Close C Program Set Active Project El aen rene no asin le AEN Clean Object Fil Build i Se Library Fil gt Linker Ge Build Opti Find in Project Files Save Project Add Files to Project Remove File From Project Select Language Toolsuite Set Language Tool Locations DS40051C page 48 2003 Microchip Technology Inc Working with the Tutorial Software 3 4 2 Simulating the Project In order to simulate the program to see what the PIC microcontroller is actually doing with each instruction select the MPLAB IDE Simulator debugger Select Debugger gt Select Tool gt MPLAB SIM as shown in Figure 3 3 FIGURE 3 3 MPLAB SIMULATION w MPLAB IDE Fle Edit View Project Debugger Programmer Contigure Window Help y Select Tool H C p Li H Ba one Clear Memory k MPLAB ICD 2 PIE EN RENAN d Ger CREER E C Program Files P Hal MPLAB ICE 2000 Source Files Step Into Ge o io state asm ellas MPLA Sli Once MPLAB SIM is selected five buttons will appear on the right end of the menu toolbar as shown in Figure 3 4 FIGURE 3 4 SIMULATION TOOLBAR WA pmg These buttons allow the user to Run code P Pause code LO Single Step code through functions Single Step code but run through the functions Reset code go oe a N To view the code in single steps press the single step button the cod
62. t needs to happen to exit this state and what state will it exit to Usually there is more than one answer to this question Depending on what happens while in a particular state the state machine may advance a state decrement a state or skip several states entirely As mentioned before it is generally a good idea to visually construct the state machine in the form of a flowchart Finally create a software module for each of the states and tie them together according to the flowchart just created ft 2003 Microchip Technology Inc DS40051C page 23 PICkit 1 FLASH Starter Kit User s Guide 2 4 2 2 TRANSLATING STATE MACHINES INTO ASSEMBLY AND C Implementing a state machine in C is quite simple to visualize C based state machines rely on the switch statement The following example code shows a switch statement being used as a state machine EXAMPLE 2 1 SWITCH STATEMENT switch STATE case State0 turn LEDO on break case Statel turn LED1 on break case State2 turn LED2 on break and so on default STATE State0 if for some reason a undefined state occurs re initialize the state machine Creating a state machine in assembly is a little more difficult In assembly the program flow is directed to the appropriate software module for a given state by incrementing the Program Counter by the state variable Incrementing the Program Counter is comprised of incrementing PCL
63. ue for relief under that Act Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates It is your responsibility to ensure that your application meets with your specifications No representation or warranty is given and no liability is assumed by Microchip Technology Incorporated with respect to the accuracy or use of such information or infringement of patents or other intellectual property rights arising from such use or otherwise Use of Microchip s products as critical com ponents in life support systems is not authorized except with express written approval by Microchip No licenses are con veyed implicitly or otherwise under any intellectual property rights DNV Certification Inc DNV MSC The Netherlands Accredited by the RvA ANSI RAB Z Nor DO V gt A A a m E mo eri ISO 9001 QS 9000 REGISTERED FIRM Trademarks The Microchip name and logo the Microchip logo KEELOO MPLAB PIC PICmicro PICSTART PRO MATE and PowerSmart are registered trademarks of Microchip Technology Incorporated in the U S A and other countries FilterLab microID MXDEV MXLAB PICMASTER SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U S A Accuron Application Maestro dsPIC dsPICDEM dsPICDEM net ECONOMONITOR FanSense FlexROM fuz
64. urrence of counter saturation The counter must saturate at the opposite state before the previous state can be re invoked During switch bounce the counter intermittently counts up and down The counter will progress up when the average closed to open period favors contact and down when the average period favors release The faster the switch settles in the closed or open state the faster the counter will reach the corresponding saturated condition Switch Filtering assumes when the switch is mostly closed or open the bouncing will favor the closed or open levels respectively It is possible for the counter to saturate before the switch has stopped bouncing It is unlikely that the counter will change saturation state unless the count is too short or the switch is headed in that direction Figure 2 4 outlines the software actions necessary to implement the Switch Filtering debounce method 2003 Microchip Technology Inc DS40051C page 17 PICkit 1 FLASH Starter Kit User s Guide FIGURE 2 4 TIME AVERAGED SWITCH FILTER DEBOUNCE Switch Filter Timer0 Overflow Closed FilterCount lt FilterCount gt MaxCount MinCount Increment Decrement FilterCount FilterCount FilterCount gt FilterCount lt MaxCount MinCount Turn LED1 On Turn LEDO On Turn LEDO Off Turn LED1 Off DS40051C page 18 O 2003 Microchip Technology Inc Tutorial Projects 2 3 2 Applications Reliable robust software reguires debouncing
65. vice Is Not Recognized Question Receiving message Insert Device but there is a part in the socket Answer 1 Verify the device in the socket is a PIC12F629 PIC12F675 PIC16F630 or PIC16F676 Other devices may be reported as Insert Device 2 Check for additional circuits attached to pins GPO and GP1 3 Check to see if the SW1 switch is pressed 5 2 4 Current Limit Exceeded Question Receiving error message USB Hub Current Limit Exceeded from Microsoft Windows 2000 Answer Check for shorts on the circuit board FIGURE 5 1 USB HUB CURRENT LIMIT EXCEEDED USB Hub Current Limit Exceeded AN An unknown device has exceeded the current limits of its hub port The placement of the device is highlighted in bold type USB Root Hub 2 ports k Unused Pout General purpose USB Hub 4 ports Unknown USB Device H Unused Port Ga HID compliant mouse en Unused Port Recommendation Disconnect the device and then click Reset to re enable the pot If you click Close a reboot will be required to regain the port DS40051C page 56 2003 Microchip Technology Inc Troubleshooting 5 2 5 Windows Driver Question After plugging the PICkit 1 into the USB port Windows 98 SE asks for a driver Where is the driver Answer PICkit 1 uses the drivers included with Windows When Windows 98 SE prompts for a driver select Search for the best driver for your device Then select t
66. zyLAB In Circuit Serial Programming ICSP ICEPIC microPort Migratable Memory MPASM MPLIB MPLINK MPSIM PICC PICkit PICDEM PICDEM net PowerCal Powerlnfo PowerMate PowerTool rfLAB rfPIC Select Mode SmartSensor SmartShunt SmartTel and Total Endurance are trademarks of Microchip Technology Incorporated in the U S A and other countries Serialized Quick Turn Programming SQTP is a service mark of Microchip Technology Incorporated in the U S A All other trademarks mentioned herein are property of their respective companies 2003 Microchip Technology Incorporated Printed in the U S A All Rights Reserved CH Printed on recycled paper Microchip received QS 9000 quality system certification for its worldwide headquarters design and wafer fabrication facilities in Chandler and Tempe Arizona in July 1999 and Mountain View California in March 2002 The Company s quality system processes and procedures are QS 9000 compliant for its PICmicro 8 bit MCUs KEELOQ code hopping devices Serial EEPROMs microperipherals non volatile memory and analog products In addition Microchip s quality system for the design and manufacture of development systems is ISO 9001 certified DS40051C page ii 2003 Microchip Technology Inc S PICkit 1 FLASH STARTER KIT MICROCHIP USER S GUIDE Table of Contents P IST EEN 1 Chapter 1 Using the PICkit 1 FLASH Starter Kit bF o de el Led Le asii iii 5

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